Underwater separable connector



Dec. 30, 19.69 I F. MASSA 3,487,353

UNDERWATER SEPARABLE CONNECTOR Filed Aug. 14, 1967 2 Sheets-Sheet 1 INVEN TOR FRANK MASSA Dec. 30, 1969 I F. MAssA NDERWATER SEPARABLE CONNECTOR2 Sheets-Sheet 2 Filed Aug. 14, 196'? l llll ll Q l--N- M/I/V/VMIIIIIH.

(/WE/VTOR FRANK MAssA MW United States Patent Mass.

Filed Aug. 14, 1967, Ser. No. 660,328 Int. Cl. H01r 13/54 US. Cl. 3398917 Claims ABSTRACT OF THE DISCLOSURE A block of rigid insulatingmaterial has a number of precisely located holes drilled therein, eachto receive an electrical terminal, which may be either a plug or asocket. Then, wires are attached to the terminals. After the wires areso attached, the region of attachment is cast in a rigid pottingcompound to provide mechanical protection for the points of attachment.Finally, a waterproof jacket is molded around the entire assembly ofinsulating material, wires, and potting compound, thus leaving only theterminals exposed outside the jacket. Then, two cables may be joined bymaking suitable plug and socket connections, after which a pair ofthreaded clamping rings are joined to prevent the connections from beingpulled apart.

This invention relates generally to separable electrical connectors andmore particularly to new and improved connectors for use in underwaterapplications.

Underwater electrical connectors of the described type generally have arubber-like jacket which is bonded to the outer covering of anunderwater cable. The cable includes a number of insulated conductorswhich are attached to a connector having either a set of plug terminalsor a set of socket terminals. Another similar cable has its insulatedconductors connected to a similar connector including the matingterminals. Thus, these two cables may be joined together by makingsimple plug and socket connections. Both the plug and socket terminalsare molded within a rubber-like envelope which fills the space betweenthe insulated conductors and these terminals with a waterproof bond. Themolded envelope also surrounds and makes a waterproof bond with therubber-like jacket of the cable.

There are many problems where this type of construction is used. A firstproblem is that the junction between cable wires and connector terminalsexperiences an undue amount of mechanical stress when heat is appliedduring the molding of the rubber-like envelope. There is a tendency forthe heated rubber-like compound to exert high pressures against theconductors, thus causing them to be crushed together. Also, the heatedcompound causes a considerable stretching of the copper strands. In somecases, there is a complete separation of the-strands which form theconductors. Worse still, the separation of the strands might not becomplete, and the joint may pass inspection. In these instances, perhapsonly a single strand remains for completing the electrical circuit.Then, if an appreciable current flows through the cable, the reducedarea of the copper conductor causes localized heating with a resultingfailure during operation. Usually, these potential faults may be foundby an X-ray inspection, but that is an expensive manufacturing step.

The second problem that results from the conventional construction isthat the locations of the plugs and sockets cannot be accuratelymaintained within the rubber-like compound. Although the plugs andsockets are held in the mold during the molding operation, a variationin the dimensions of the rubber-like compound sometimes ocice cursduring cooling after the part is removed from the mold. These variationstend to cause the terminals to shift somewhat from their ideal location,and that shift, in turn, requires larger tolerances between the plug andsocket parts. These relaxed tolerances are particularly disadvantageouswhen several terminals are located within a relatively small sizeconnector.

A third problem arises when the rubber-like compound flows throughclearance portions of the mold to form an unwanted thin layer or fin ofmaterial, often called a flash. This flow is especially troublesome inthe regions where the plugs and sockets are mounted because the flashwhich might surround a portion of the plugs and sockets is extremelydifficult to remove especially when it is located within a recessedregion of the connector assembly. As a result, an intermittent troubleoccurs because there is an electrical contact which makes and breaks atrandom due to the high resistance of the rubber flash between varioussurfaces of the plugs and sockets.

Still another problem found in the conventional construction resultswhen the connector is used in deep water applications where thehydrostatic pressure may eX- ceed 1000 p.s.i. This high pressure isimpressed on the rubber-like jacket in the region of the junctionsbetween the cable conductors and terminals. In some instances, thisimpression has caused a jacket deformation to an extent which forces theconductors together and causes an electrical breakdown under highpressure conditions.

Accordingly, an object of the invention is to provide new and improvedseparable connectors for underwater cables. More particularly, an objectis to provide underwater connectors which are much more reliable thanthose used heretofore. In this connection, an object is to provideconnectors which are reinforced at the junction point between the wiresin the cable and the terminals in the connector.

Still further, an object is to provide improved structures which are notsubject to failures caused by heating, pressures, stresses, and thelike, which normally occur during conventional manufacturing processes.Here, an object is to provide a rigid mounting structure for holding theconnector terminals in accurate alignment during molding operation whilethe connector is being covered by a waterproof jacket. A further objectis to encase the wires of the cable in a rigid, protective, pottingcompound at the points where they join the connector terminals.

In keeping with an aspect of the invention, these and other objects areaccomplished by the use of a rigid block of insulating material havingholes accurately drilled therein for receiving either plug or socketterminals. The wires in the underwater cable are connected to theseterminals. Then the junctions between these wires and the terminals areencased by a potting material which surrounds, strengthens, andreinforces the wires to protect themespecially during the manufacturingprocess. Thereafter, a molded rubber-like jacket is formed around theentire assembly to make it waterproof.

The nature of a preferred embodiment of the invention may become moreapparent from a study of the attached drawings, in which:

FIG. 1 is a perspective view of two cable sections joined by theinventive connector;

FIG. 2 is a cross-sectional view (taken along line 22 of FIG. 1) of theplug half of an underwater connector embodying the teachings of thisinvention;

FIG. 3 is an end view of the plug half of the connector taken along theline 33 of FIG. 2;

FIG. 4 is a perspective view of a clip used to interconnect a cable wireand a terminal plug;

FIG. 5 is a cross-sectional view (taken along the line 5-5 of FIG. 1)showing the socket half of the connector 3 corresponding to the matingportion of the plug half illustrated in FIG. 2;

FIG. 6 is a perspective view of the socket terminal; and

FIG. 7 is an end view taken along the line 7-7 of FIG. 6.

FIG. 1 shows two underwater cables 20, 21 each of which includes anysuitable number of wiressuch as the exemplary two wires shown at 22, 23.These cables preferably have waterproof, rubber-like outer jackets.These wires are, respectively, connected to terminals in a plug half ofa connector 24 and a socket half of a connector 25. Then, a waterproofjacket is molded over each of these connector halves. For example, theplug half 24 is covered by a jacket beginning at 26 with a waterproofbond to the cable and ending at 27 in a molded flange (not visible inFIG. 1). Likewise, the socket half is also covered by a jacket beginningat 28 with a waterproof bond to the cable 21 and ending at a moldedflange near 29. A pair of mating threaded ring clamps fit over thejacket flanges. When these threaded ring clamps are joined and theknurled ring 30 is turned, the jacket flanges are squeezed together tomake a waterproof bond between the two halves 24, 25.

For a better understanding of the plug half 24 of the connector,reference may be made to FIG. 2 which also shows the cable 20, wires 22,and jacket 26-27. In addition, it shows two plug terminals 35, 36. Theplug terminal 36 is smaller, both in length and diameter, than the plugto provide an index so that the two halves 24, 25 may not be joinedimproperly to reversely interconnect the wires in the two cables. Ofcourse, the invention also contemplates other forms of indexing such askeys and key slots, for example. Or the plugs 35, 36 could beunsymmetrically located about the central axis of the connector half.

Means are provided for maintaining accurate terminalpositions-especially during the manufacturing process. In greaterdetail, a rigid block of insulating material 37 (conveniently in theform of a cylinder) is provided with precisely drilled clearance holesfor receiving the stern portions 38, 39 of the plug terminals 35 and 36.During manufacture, the plug terminal stems 38, 39 are inserted into theclearance holes in the block of insulating material 37. Then, theinsulation on the conductors 22 is stripped, and the conductor wires 40,41 are electrically connected to the plug stems 38, 39, as by means ofmetal clips 42, 43. These clips form mechanical and electrical junctionsbetween the conductor wires 40 and 41 and the plug stems 38, 39,respectively. An example of such a clip is shown by the large scaledetail drawing of FIG. 4. Dotted lines are used at to indicate that themetal clips 42 and 43 may be inserted in the insulating material 37 sothat they also serve as an anchor for attaching the plugs 35, 36 to theblock of insulating material 37.

After making the electrical connections via clips 42, 43, the region inthe vicinity of the clips is filled with a rigid potting conipound 46.First, a cap 47 is attached over the end of the cable 20, and then theend of the insulator block 37 is fitted against the end of cap, asillustrated. Next, the space within the cap 47, is filled with asuitable potting compound which is poured through a small hole 48 in thewall of the cap. The .cap 47 may consist of a molded rubber-like sleevewhich may be left in place permanently after the potting 46 has beenpoured. Or it could be a separable metal mold. Preferably, the pottingcompound is an epoxy that can be poured in place and then become rigidwithout requiring an application of any pressure upon the wires 40, 41or clips 42, 43.

It should be noted that, at this point in the construction, a rigidsubassembly has been achieved to locate the junction between cable wires22, the plug terminals, and the rigid insulator block 37. Thissubassembly is very strong and is not subject to the faults of prior artstructures. Moreover, it is not easily damaged by any heat or pressurewhich may be encountered during further manufacturing.

During a final molding operation, a rubber-like compound is applied overthe assembly described thus far in order to form the waterproof outerjacket 49 which covers the rigid insulator block 37 and the taperedepoxycast region 46. This compound forms a long tapered portion flaringsmoothly from the cable 20 to a jacket flange 50. A relatively heavywall of rubber is molded to form a recessed cup-like cavity 51 withinwhich the plug terminals are contained. A loose ring clamp 52, fits overthe flange 50, is provided with outer threads 53. Among other things,this jacket and ring clamp combination provides a suitable strain reliefduring bending while the cable is In use.

FIGS. 5-7 illustrate the construction of the socket half 25 of theconnector assembly. The general construction of this half is similar tothat described in connection with FIG. 2. A rigid block of insulatingmaterial 60 is provided with precisely located clearance holes 61, 62located to correspond with the spacing of the plugs 35, 36. These holesare counterbored from the opposite end, thus leaving a shouldered region63, 64 near the upper surface. A tubular socket type connector 66, 67 isinserted from the bottom of the counterbored holes 61, 62 and isretained by the shoulder 63, 64 at the top of the hole.

An enlarged illustration of the socket terminal is shown in FIGS. 6 and7. More particularly, a thin strip or plate of Phosphor bronze,beryllium copper, or any other suitable conductor material, having goodspring characteristics, is blanked and then rolled-up to form acylindrical tube 70. During the blanking step, three Windows aresemipierced in the cylinder wall to provide three elongated contactterminals 71, 72, 73, each of which remain attached at one end to thewall 70. The other ends of the elongated terminals are pushed inwardlyso that they are deflected toward the center of the cylindrical shell 70with a taper which flares in the direction of plug travel. Thus, thetips of these elongated terminals make good contacts with the plugs. Thebottom end of the socket member is provided with a terminal lug 75 whichis used to make electrical contact and retain the cable wire 76, whichis one of the wires 23.

Another socket terminal in the hole 62 is similar to that illustrated inFIGS. 6, 7 except that it is somewhat smaller in diameter and isdimensioned to receive the plug 36. This prevents reversal of the plugand socket connections because the plug 35 is too large to fit into thesocket in hole 62.

Before an attachment of the conductors 76 to the socket terminal lugs75, a washer 78 (FIG. 5), preferably of a rubber-like material andhaving small clearance holes for the terminal lugs 75 or wires 76, isslipped over the wires. After the conductors are crimped into the lugs75 of the socket terminals 66, 67, the washer 78 is cemented to the baseof the rigid insulator block 60 by using any one of the many well knownrubber cements or epoxies. This washer is provided to seal the bottom ofthe insulator block 60 to prevent the epoxy 46 from seeping into thesocket terminal area. A molded tapered cap 47 is utilized to retain therigid potting compound 46 and to consolidate the subassembly of thesocket terminal assembly 25 into a rigid unit.

The next step in the manufacturing procedure is to mold the rubber-likeouter jacket 49 around the subassembly of FIG. 5. The molded surfaces83, 84 around the periphery of the insulating member 60 and the innerdiameter of the cavity 51 are preferably made to have an interferencefit to increase the waterproof qualities of the connector. A flangeportion 80, which corresponds in shape and size to the flange portion50, is provided as part of the jacket 49. The flange 80 also includes asmall raised bead 81 which acts as an O-ring seal when the two connectorhalves 24, 25 are engaged. Surrounding the connector 25 is a rigid ringclamp member. 3%

that has internal threads 82 which engage the threads 53 on the ringclamp 52. After the two connector halves are engaged, it is impossibleto pull the connector halves apart if they are exposed to heavy tensilestresses such as may occur in turbulent seas or when a heavy structureis attached to the opposite end of one of the cables 20, 21. These ringclamps also squeeze the flanges 50, 80 together to form a waterproofseal.

The advantages of the invention should now be clear to those skilled inthe art. More particularly, the use of the spring-like contacts 71-73provides positive a low resistance electrical connection. Due to therelatively long spring that is achieved by the design, it is impossiblefor the flexible members to take a permanent set when the plugs areinserted. Also, if an oversize plugis inserted into the socket, there isno permanent set to cause an erratically high contact resistance ifsubsequently an undersized plug is inserted. The location of the plugand socket connectors are accurately and permanently maintained by therigid insulating block retainer. The use of this rigid block ofinsulation material, in conjunction with the epoxy potting, consolidatesthe junction region in which electrical connections are made betweenthe' cable conductors and the connector terminals. This prevents thedisplacement of the conductors during subsequent molding operations andwhen the connection is subject to high hydrostatic pressures, such asoccur in deep water.

Experimental data has shown that the type of connector just describedusing pin contacts as small as diameter results in a contact resistancein the order of a few milliohms when unplated brass terminals andPhosphor bronze or beryllium copper sockets are used. When silverplating is employed, this already insignificantly low contact resistancebecomes even lower.

This invention has been described in connection with particularembodiments which illustrate the basic principles of the invention.However, it will be obvious to those skilled in the art that numerousdeviations are possible without departing from the principles shown anddescribed herein. Therefore, the invention should not be limited to thisparticular structure, but should be construed to cover all equivalentsfalling within the true spirit and scope of the invention.

I claim:

1. A separable underwater electrical connector comprising a rigid blockof insulating material, terminal means in said block, an electricalcable having at least one electrical conductor therein and which isconnected to said terminal means, said cable being surrounded by awaterproof outer jacket, said connection being made in a region boundedat one side by .a surface of said block of insulating material and atthe opposite side by the cable jacket, a solid electrical insulatingmaterial filling the space within said bounded region, and a secondmaterial surrounding said block and said electrical insulating material,said second material being bonded to both the periphery of the cablejacket and the periphery of said block of insulating material to form awaterproof covering for said connector.

2. The invention set forth in claim 1, characterized in that saidelectrical insulating material is a rigid potting compound.

3. A separable underwater electrical connector comprising a solid blockof insulating material having holes precisely formed therein, electricterminal means located in said holes, insulated electrical conductormeans connected to said terminal means, said conductor means beingenclosed within a waterproof jacket, solid electrical insulation pottingmaterial surrounding the region occupied by the terminal connections andextending from said block of insulating material to the surface of saidcable jacket, and pliable waterproof material surrounding said solidelectrical insulation potting material and bonded at one end to saidwaterproof jacket and at the other end to said block of insulatingmaterial.

4. The invention set forth in claim 3 wherein half of said connectorincludes a plurality of sockets for receiving plugs in another half whensaid halves are joined, each of said sockets comprising a cylinder ofelectrically conductive spring material having at least one semipiercedwindow defining an elongated tongue of electrically conductive materialbending inwardly toward the center of said cylinder, the axis of saidcylinder coinciding with the elongated dimensions of said tongue, and aterminal lug on each of said sockets for completing an electricalconnection.

5. The connector of claim 4 wherein each of said sockets includes aplurality of semipierced windows spaced around the circumference of saidcylinder, there being an elongate tongue of electrically conductivematerial in each of said windows.

6. Theconnector of claim 4 wherein a potting material surrounds andreinforces the area where the electrical connections are made with saidterminal lugs.

7. In combination in a separable underwater electrical connector formedby first and second halves for providing plug and socket connections,each of said halves including a block of insulating material, each ofsaid blocks having a common axis of reference, a plurality of plugterminal means located within a block in a first of said halves, aplurality of socket terminal means located within a block in a second ofsaid halves, said plug and socket terminals having the same relativespacing with respect to said common axis of reference so that saidterminals will engage each other when the two halves are broughttogether, an electrical cable having a plurality of insulated conductorssurrounded by a waterproof outer jacket, a first length of said cablehaving its conductors connected to said plug terminals, another lengthof said cable having its conductors connected to said socket terminals,rigid insulation potting material surrounding the junction regionsoccupied by the connections between the conductors and terminals, saidpotting material extending from the surface of said insulating blocks tothe surface of the waterproof cable jacket, and a pliable waterproofmaterial surrounding the said rigid insulation potting materials andbonded to the cable jackets and said blocks of insulating materials.

8. The invention set forth in claim 7 characterized in that said pliablewaterproof material is molded of a rubber-like material.

9. The invention set forth in claim 7 in which said pliable waterproofmaterial on each of said halves has a rugged flange portion, each ofsaid flanges having a plane face at right angles to said axis ofreference, and further characterized in that said plane faces of saidflange portions meet when the halves are assembled.

10. The invention set forth in claim 9 further characterized in that acircular bead is molded into the face of at least one of the flangeportions to serve as an O-ring seal when the two flange faces arepressed together.

11. In combination in a separable underwater electrical connector formedby first and second halves for providing plug and socket connections,each of said halves including a block of insulating material, each ofsaid blocks having a common axis of reference, a plurality of plugterminal means located within a block in a first of said halves, aplurality of socket terminal means located within a block in a second ofsaid halves, said plug and socket terminals having the same relativespacing with respect to said common axis of reference so that saidterminals will engage each other when the two halves are broughttogether, an electrical cable having a plurality of insulated conductorssurrounded by a waterproof outer jacket, a first length of said cablehaving its conductors connected to said plug terminals, another lengthof said cable having its conductors connected to said socket terminals,rigid insulation potting material surrounding the junction regionsoccupied by the connections between the conductors and terminals, apliable waterproof material surrounding the said rigid insulationpotting materials and bonded to the cable jackets and said blocks ofinsulating materials, said pliable waterproof material on each of saidhalves having a rugged flange portion, each of said flanges having aplane face at right angles to said axis of reference, characterized inthat said plane faces of said flange portions meet when the halves areassembled, and a threaded ring clamp fitted over each flange portion,said ring clamps having mating threads for making a mechanicalconnection between said halves when said threaded ring clamps are joinedwhereby the mating flange surfaces of said halves are squeezed tightlytogether in a sealed face-to-face contact.

12. In combination in a separable underwater electrical connector formedby first and second halves for providing plug and socket connections,each of said halves including a block of insulating material, each ofsaid blocks having a common axis of reference, a plurality of plugterminal means located within a block in a first of said halves, aplurality of socket terminal means located within a block in a second ofsaid halves, said plug and socket terminals having the same relativespacing with respect to said common axis of reference so that saidterminals will engage each other when the two halves are broughttogether, an )electrical cable having a plurality of insulatedconductors surrounded by a waterproof outer jacket, a first length ofsaid cable having its conductors connected to said plug terminals,another length of said cable having its conductors connected to saidsocket terminals, rigid insulation potting material surrounding thejunction regions occupied by the connections between the conductors andterminals, a pliable waterproof material surrounding the said rigidinsulation potting materials and bonded to the cable jackets and saidblocks of insulating materials, said pliable waterproof material on eachof said halves having a rugged flange portion, each of said flangeshaving a plane face at right angles to said axis of reference,characterized in that said plane faces of said flange portions meet whenthe halves are assembled, and further characterized in that a circularhead is molded into the face of at least one of the flange portions toserve as an O-ring seal when the two flange faces are pressed together,and a threaded ring clamp fitted over each flange portion, said ringclamps having mating threads for completing a mechanical connectionbetween said threaded rings whereby the mating flange surfaces of saidhalves are held tightly together in sealed face-to-face contact.

13. The method of fabricating a separable underwater connector includingthe following steps: (1) assemble a plurality of electrical terminalswithin a rigid block of insulating material, (2) mechanically andelectrically connect the conductors of a jacketed cable to saidterminals, (3) confine a region in the vicinity of the terminal andconductor connections by means of a surrounding sealed enclosure whichextends from the surface of the insulating terminal block to the surfaceof the cable jacket, (4) pour an electrically insulating liquid pottingcompound into said sealed enclosure to form a body member, said compoundbeing one which sets up solid without an application of pressure, and(5) mold a rubber-like material around the potted conductor and terminalassembly, said rubber-like material being bonded to the periphery of thecable jacket and enclosing the body member to form a waterproof jacket.

14. A separable underwater electrical connector formed by first andsecond halves for providing plug and socket connections, each of saidhalves including a rigid block of insulating materal, a plurality ofplug terminal means located within the rigid block in a first of saidhalves, a plurality of socket terminal means located within the rigidblock in a second of said halves, said plug and socket terminalsengaging each other when the two halves are brought together, a firstlength of Waterproof jacketed cable having its conductors connected tosaid plug terminals, another length of waterproof jacketed cable havingits conductors connected to said socket terminals,

rigid insulation potting material surrounding the junction regionsoccupied by the connections between the conductors and terminals, saidpotting material filling the entire region from the cable jacket to therigid insulating block, a pliable waterproof material surrounding thesaid rigid insulation potting materials and said blocks of insulatingmaterials, the waterproof material surrounding said plug terminalsforming a cavity in which said plug terminals are completely recessed,and the waterproof material surrounding said socket terminals forming aplug-section having contours which are complementary to the contours ofsaid cavity and dimensioned to have an interference fit with said cavitywhen said first and second halves come together.

15. A separable underwater electrical connector formed by first andsecond halves for providing plug and socket connections, each of saidhalves including a rigid block of insulating material, a plurality ofplug terminal means located within the rigid block in a first of saidhalves, a plurality of socket terminal means located within the rigidblock in a second of said halves, said plug and socket terminalsengaging each other when the two halves are brought together, a firstlength of cable having its conductors connected to said plug terminals,another length of cable having its conductors connected to said socketterminals, rigid insulation potting material surrounding the junctionregions occupied by the connections between the conductors andterminals, a pliable waterproof material surrounding the said rigidinsulation potting materials and said blocks of insulating materials,the waterproof material surrounding said plug terminals forming a cavityin which said plug terminals are completely recessed, the waterproofmaterial surrounding said socket terminals forming a plug-section havingcontours which are complementary to the contours of said cavity anddimensioned to have an interference fit with said cavity when said firstand second halves come together, said pliable waterproof material oneach of said halves having a rugged flange portion, each of said flangeshaving a plane face at right angles to the plug and socket terminalsrespectively so that said plane faces of said flange portions meet whenthe halves are assembled, and a ring clamp surrounding each of saidflanges to lock said two halves together.

16. The invention set forth in claim 15 and a circular bead molded intothe face of at least one of the flange portions to serve as an O-ringseal when the two flange faces are pressed together by said ring clamp.

17. In combination in a separable underwater electrical connector formedby first and second halves for providing plug and socket connections,each of said halves including a block of insulating material, each ofsaid blocks having a common axis of reference, a plurality of plugterminal means located within a block in a first of said halves, aplurality of socket terminal means located within a block in a second ofsaid halves, said plug and socket terminals having the same relativespacing With respect to said common axis of reference so that saidterminals Will engage each other when the two halves are broughttogether, an electrical cable having a plurality of insulated conductorssurrounded by a waterproof outer jacket and connected to the terminalmeans in at least one of said halves of said connector, rigid insulationpotting material surrounding the junction regions occupied by theconnections between the conductors and terminal means, said pottingmaterial extending from the surface of said insulating block in said onehalf to the surface of the waterproof cable jacket, and a pliablewaterproof material surrounding the said rigid insulation pottingmaterial, said pliable waterproof material being bonded to the cablejacket and said block of insulating material of said one half.

(References on following page) References Cited UNITED STATES PATENTSSharp 339-89 Ley et a1. 339-89 Doane.

Phillips 339-89 Honig 339-89 King 339-59 -Filson 339-258 Piscitello eta1. 339-88 Mittler et a1. 339-18 Parnell 339-94 10 FOREIGN PATENTS1,250,743 12/ 1960 France.

9,895 8/ 1956 Germany. 351,474 6/ 1931 Great Britain. 955,432 4/ 1964Great Britain.

MARVIN A. CHAMPION, Primary Examiner J. H. McGLYNN, Assistant ExaminerUS. Cl. X.R.

